a) x2 - 3x = 0
<=> x.(x - 3) = 0
<=> x = 0 hoặc x - 3 = 0
<=> x = 0 hoặc x = 3
b) 2.(x - 2) + (2 - x) = 0
=> 2x - 4 + 2 - x = 0
<=> (2x - x) - (4 - 2) = 0
<=> x - 2 = 0
<=> x = 2
a) x(x-3)=0
+ x=0
+ x-3=0 <=> x=3
S={0;3}
b) (x-2)(2x-1)=0
+x-2=0 <=> x=2
+2x+1=0 <=> x=-1/2
S={ 2; -1/2}
a) x2 - 3x = 0
<=> x( x - 3 ) = 0
<=> \(\orbr{\begin{cases}x=0\\x-3=0\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=0\\x=3\end{cases}}\)
b) 2x( x - 2 ) + ( 2 - x ) = 0
<=> 2x( x - 2 ) - ( x - 2 ) = 0
<=. ( 2x - 1 )( x - 2 ) = 0
<=> \(\orbr{\begin{cases}2x-1=0\\x-2=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=\frac{1}{2}\\x=2\end{cases}}\)